《灵枢·经脉》：肾足少阴之脉：起于小指之下，邪走足心，出于然谷之下，循内踝之后，别入跟中，以上踹内，出腘内廉, 上股骨内后廉, 贯脊属肾，络膀胱。

The Chapter "Discussion on the Meridians" in Miraculous Pivot says: The Kidney Meridian starts from the inferior aspect of the small toe and runs obliquely towards the sole. It comes out from Rangu(KI2), runs behind the medial malleolus and enters the heel. Then it ascends along the medial side of the leg to the medial side of the popliteal fossa and goes further upward along the posterior medial aspect of the thigh towards the vertebral column, where it enters the kidney, its pertaining organ, and connects with the bladder.

其直者：从肾，上贯肝、膈，入肺中，循喉咙,挟舌本。

The straight portion of meridian re-emerges from the kidney. Ascending and passing through the liver and diaphragm, it enters the lung, runs along the throat and terminates at the root of the tongue.

A branch springs from the lung, joins the heart, and runs into the chest.